Kruskal-Wallis analysis indicated that the primary axis of variation showed no relationship to habitat preference (χ2 = 2.29, df = 1, P = 0.1306); however, it correlated with a quantitative shade tolerance metric, WPLCP (Fig. 2).
To achieve these goals, an effective molecular dissection of these complex quantitative stress tolerance and yield-contributing traits by identification (map-based cloning) of potential trait-associated genes/quantitative trait loci (QTLs) through genetic/association mapping and their deployment in marker-assisted genetic enhancement of chickpea is essential.
In addition, ten drought tolerance quantitative trait loci (QTL) associated with tolerance in seedlings have been mapped in cowpea [ 13].
The majority of accessions display a strong quantitative relationship between tolerance and leaf blade Na+ concentration, and thus the major tolerance mechanisms found in these species are those contributing to limiting sodium uptake and accumulation in active leaves.
Under such circumstances, a transgenic approach to the problem seems more convincing and practicable, and it is being pursued vigorously to improve qualitative and quantitative traits including tolerance to biotic and abiotic stresses in different crops.
These researchers noted that some of the induced genes fell into physical clusters on the rice chromosomes, including a region associated with a salt-tolerance quantitative trait locus (QTL).
In Arabidopsis, the major Al tolerance quantitative trait loci (QTL) was proposed to be proximal to the AtALMT1 malate transporter and to involve additional genes [ 14].
Nagina22 is an upland rice variety known for its tolerance to drought stress and is an international standard in drought breeding programmes and studies on dissection of drought tolerance quantitative trait loci/genes in rice.
Accordingly, by acute toxicity assays we have demonstrated quantitative differences in tolerance to ammonia between the urban population of the M form in Yaounde compared to the parapatric population of the S form occurring in neighbouring rural settings.
The present study aimed to identify positional candidate genes for a major freezing tolerance quantitative trait locus that was previously mapped to M. truncatula chromosome 6 (Mt-FTQTL6) using the LR3 population derived from a cross between the freezing-tolerant accession F83005-5 and the freezing-sensitive accession DZA045-5.
